Administration Guide

Viewing Metadata

The Data Services Metadata Browser, a component of the AquaLogic Data Services Platform Console, enables you to view information on data services, their functions, and their dependencies in the currently active WebLogic Server.

This chapter describes how to use the MetaData Browser, and includes the following sections:

Introducing the MetaData Browser

The MetaData Browser enables you to view metadata related to a AquaLogic Data Services Platform deployment. The information includes the data services that are deployed, their functions and return types, dependencies between data services, and more. Essentially, metadata documents the data model represented by the AquaLogic Data Services Platform deployment.

Search for metadata in an application or project. You can perform basic or advanced searches on metadata in an application or in a project folder. For more information, see
Searching Metadata on page 8-13.

Using the Metadata Browser

You can use the MetaData Browser to introspect both data service metadata and function metadata.

Metadata Browser Requirements for Data Lineage Graph

The Table 8-1 outlines the browser requirements to ensure visibility of the data lineage graph. If your system does not meet the requirements stated in the table, revert to the tabular view of the Metadata Browser.

The Adobe® SVG Viewer plugin required for Internet Explorer and Netscape can be downloaded from:

Can auto-detect SVG viewer. If SVG viewer is not installed, a message is displayed with the URL to download the viewer. Install the viewer and the data lineage graph will be visible instantly.

On Windows platform only.

Netscape (8.0)

Can auto-detect SVG viewer. If SVG viewer is not installed, a message is displayed with the URL to download the viewer. Install the viewer and the data lineage graph will be visible instantly.

On Windows platform only.

You need to add the URL to the list of trusted sites to view the data lineage graph. Perform the following steps:

Click the Open Site Controls icon on the browser tab when you log in to the Administration Console.

In the pop-up dialog box, select the I trust this site radio button.

Click Done to save your preference.

This will enable you to view the data lineage graph.

Mozilla Firefox (1.5)

Has native SVG viewer support.

On Windows and Linux platforms.

The data lineage graph is visible without the zoom in or zoom out operations. However, you can scroll up and down using the scroll bar.

Metadata Browser Interface for Data Services

You can browse data service metadata including general information about a specific data service, its data lineage, its read functions and return types, relationships, dependencies, and more using the Metadata tab in the AquaLogic Data Services Console.

To browse data service metadata:

Select a data service in the Navigation pane. The Admin/Metadata screen appears (Figure 8-1). The Metadata tab in the console displays general information about the metadata associated with the data service.

Displays a table of read functions. The table also lists the parameter names, if any, and return type (schema file name) for each function.

Return Type

Displays the content of the schema associated with the return type of the data service.

Relationships

Displays a table of related read functions. The table also lists the parameter names, if any, and return type (schema file name) for each function.

Properties

Lists any user-defined properties assigned to the data service.

Lineage

Provides a visual representation of the lineage between the currently selected data service. Relationships can be displayed in one of the two possible directions:

Dependencies

Where used

Each entry includes name and path information.

Data Service Lineages

Data service lineages can be viewed in graphical or tabular format. The graphical view is ideal for getting a visual understanding of the lineage associated with a particular data service.

To start with, select a data service from the Navigation pane.

There are two ways to view a data service lineage:

Where used view. The currently selected data service and the data services which make use of it appear. This is the downstream view.

Dependency view. The currently selected data service and the data services it is dependent upon appear. This is the upstream view.

Data service dependencies associated with navigation functions are shown based on the following rules:

If a data service contains a read function which calls a navigation function, the data service containing the navigation function appears as a dependency.

If the data service contains a navigation function that calls a read function (such as the constructor function in the related data service), that relationship is insufficient for the data service to be identified as a dependent.

The reason for this is that navigation functions are often created automatically during the import metadata process. For details see "Obtaining Enterprise Metadata," in the Data Services Developer's Guide.

Figure 8-2 OrderView Data Service and Its Dependents

Once visual rendering appears, several options become available:

Panning (Alt + Click, then drag). Allows you to move through the lineage representation in any direction.

Zoom out (Ctrl + Shift + Click). Allows you to zoom out, providing information on data services that are further removed from your current selection.

Zoom in (Ctrl + Click). Allows you to zoom in on a set of data services.

Expanding/Contracting. You can use the +/- sign adjacent to the object to expand or collapse that node.

You can navigate to a new data service simply by double-clicking on it in the lineage diagram.

Note:

Panning and Zoom operations work only with the Adobe SVG Viewer.

Introspecting Data Service Metadata

There are two types of data services:

Physical data services. These represent a single data source, typically a relational database table, stored procedure, or a web service.

Logical data services. These can be composed from multiple data sources and represent a view of data which typically is not available from any single data source.

The metadata that is available through the MetaData Browser varies depending on whether a data service is physical or logical. Logical data sources always have dependencies while the physical data services always have dependents.

Figure 8-3 illustrates a tabular view of dependencies and where used information of a logical data service.

Figure 8-3 Logical Data Service Dependencies and Where Used

As you would expect of a logical data service, the return type displays the schema of the data from multiple data sources, according to the design of the data service, as illustrated in Figure 8-4.

Figure 8-4 Return Type for a Logical Data Service

Metadata Browser Interface for Data Service Functions

You can browse metadata associated with a function.

To display function metadata:

Select a function in the Navigation pane.

The console displays the General metadata associated with the function.

Click the corresponding tab to display general information, function dependencies, where used information, properties, and the return type.

General metadata information for the function, including the following:

Function name. The name of the function.

data service. The containing data service.

Description. A user-supplied description of the function.

Return Type. The type returned by the function.

Lineage

Provides a visual representation of the relationships between the currently selected data service read, navigation, or private function. Lineage can be displayed in one of the two possible directions:

Dependencies

Where used

Each entry includes name, path, and type information.

Properties

Displays any user-defined properties associated with the function.

Return Type

Displays details about the return type of the function.

Data Service Function Lineages

Data service function lineages can be viewed in graphical or tabular format. The graphical view is ideal for getting a visual understanding of the lineage associated with a particular function. The view includes all functions that directly or indirectly call your selected function, or are called by your selected function.

To start with, select a data service from the Navigation pane. Click on the data service and then select from the list of available read or relationship functions.

There are two ways to view a data service function lineage:

Dependency view. The currently selected data service function and any functions that it calls (said another way, it depends upon).

Where used view. The currently selected data service function and any functions that make use of it (said another way, depend on it).

Figure 8-6 OrderView Data Service and Its Dependents

Once visual rendering appears, several options become available:

Panning (Alt + Click, then drag). Allows you to move through the lineage representation in any direction.

Zoom out (Ctrl + Shift + Click). Allows you to zoom out, providing information on data services that are further removed from your current selection.

Zoom in (Ctrl + Click). Allows you to zoom in on a set of data services.

Expanding/Contracting. You can use the +/- sign adjacent to the object to expand or collapse that node.

You can navigate between functions simply by double-clicking on the particular function of interest that appears in your graph. Lineage for both read and relationships functions can be traced.

Cyclic Dependency

Cyclic dependency can be observed in a graphical view of both data service lineages and data service function lineages. If a data service is used more than once, each instance of the data service in the graphical view is indicated in a dark blue color. Similarly, if a data service function is used more than once, each instance of the data service function in the graphical view is indicated in a dark blue color. Cyclic redundancy is applicable only when the duplicating nodes are part of the same branch.

Figure 8-7 shows the cyclic dependency of a data service. The text <<Recursive is specific to a data service and is displayed only in the case of a data service dependency.

Searching Metadata

The MetaData Browser provides both a basic and an advanced search facility. You can use the search capabilities to locate data services based on metadata associated with the services. You can then generate a report using the results from either of the search modes.

Search algorithms that include wildcards are based on standards governing regular expression syntax. For detailed information on regular expression syntax see one of the following currently available Web sites:

Performing an Advanced Metadata Search

You can use the advanced search facility to narrow your search criteria in cases when a basic search produces a large number of results. Using the advanced search option, you can specify criteria such as creation date, last modified data, owner, comments, and user-defined properties.

To perform an advanced search:

Right-click on a AquaLogic Data Services Platform application or project node in the Navigation pane, and choose Search in the context-sensitive menu.

Generating Reports

You can generate an HTML report based on the results of a basic or advanced search. In preparing the report, you specify the information to include such as read functions, return type, relationships, and more.

To generate a report:

Right-click on a AquaLogic Data Services Platform application or project node in the Navigation pane, and choose Search in the context-sensitive menu.

The basic search screen appears. The advanced search tool is available as a link below the basic search interface.

Specify the criteria for either a basic or advanced search, and click Search.

The search results appear in the Contents pane.

Click Create Report in the Content pane to generate a report from the search results.

The Generate Report page appears, as illustrated in Figure 8-11, enabling you to specify the information to include in the generated report.

Figure 8-11 Generating Reports

Select the information you want to include in the report, and click Generate Report.

The generated report appears in the Contents pane. Alternative, you can click Clear to reset the Generate Report page, or click Back to Result to return to the search results.

Click Return to Explorer to exit the search facility and return to the main interface.

Table 8-6 describes the options you can select to defined the information included in the generated report.

Table 8-6 Report Information

Information

Description

Read Function

Includes read functions in the report. You can choose to include standard or summary information for each function.

Return Type

Includes the return type of the data service in the report.

Relationships

Includes related data services in the report.

Properties

Includes user-defined properties associated with the data service as part of the report.

Dependencies

Includes the data services on which the resulting data service depends. The data services listed in this table contribute content to the current function's return value.